<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
        
    </style>
</head>
<body>
    <input type="text" id="num1">
    <select id="fh">
        <option value="+">+</option>
        <option value="-">-</option>
        <option value="*">*</option>
        <option value="/">/</option>
        <option value="%">%</option>
    </select>
    <input type="text" id="num2">
    <input type="button" value="=" id="btn">
    <input type="text" readonly is="result">
</body>
<script>
    
</script>
</html>